Gypsum wall board



Dea-3o, 1930. G. A. NEW 1,787,163

GYPSUM WALL BOARD Fild March 26. 1928 :ria-J: arizxeut" Patented Dec; 30, 1.930Y

` UNITED STATES PATENT OFFICE GUSTAV ADOLPH NEW, F PORT CLINTON, OHIO, ASSIGNORTO AMERICAN GYPSUM COMPANY, OF PORT CLINTON, OHIO, A CORPORATION OF OHIO GYPSUM WALL BOARD Application led March 26, 1928. Serial No. 264,658.

This invention relates to improvements in gypsum Wall board, and more particularly to a composite building material consisting of a layer of calcined gypsum or plaster' of Paris covered on opposite sides with sheets of paper.

The object of the inventionis to provide an improved means of treating the side edges of the board in the course of manufacture in such a manner as to materially improve its structural qualities and its use of the purposes intended.

Wall board or plaster board, as it is sometimes called, is not a new product, and eX- cepty for variations the methods of forming the edges of the board, treating the materials used, and minor departures in manus facturing processes, 'the standard practice is to make the board by a continuous process machine, whereby the sheets are fed-to the machine from rol1s,the wet plaster fed between the sheets and thence between pressure or squeeze rolls which reduce the product to its desired thickness. In some processes of manufacture the edges of the board are open with the full Width of plaster exposed, although the more recent practice has been to cover or bindthe edges by folding the margins of one or both covering sheets over the side edgeseeither completely or partially sealing the plaster body at the side edges.`

Again, wall board is manufactured with the margins of the covering sheets embedded in the edges of the plaster core or body, thus providing additional reinforcement to strengthen the edge and to give three or more plies of paper through which the nails are driven when applying the board to the wall.

The present invention seeks to improve upon the various types of edge construction heretofore used or now in use, by retaining the advantages of an edge covering and reinforcement but without the attending disadvantages; the chief of which is the weakening tof the core Imaterial along the edges 'ofV the A board when there is a complete or substantially complete coverage of the edge ywith paper. As well known in the art, the board is dried in the process of manufacture to drive off the moisture in the wet plaster and since the paper covering on the edges tends to retard the drying, it is necessary to either cessive calcination of the plaster, particularly at the edges with the result that they become quite brittle and therefore easily'fractured. This condition is more pronounced along the edges than eleswhere, since the edge portions are exposed to the heat on three sides.

It is proposed therefore to eliminate paper or like fibrous material forthe covering and reinforcing material and use a woven mesh fabric, such as cloth or fine wire, the former being quite satisfactory for practical purposes. i l

The following is a description of the manner in which wall board is constructed in accordance with my invention together with a disclosure of a practical method of manufacturing such a product:

In the accompanying drawings, y

Figure 1 is a view in cross section through the edge of a piece of wall board showing the preferred method of disposing the covering and reinforcing material at the edge.

Figure 2 is a perspective view of a piece of wall board with portions broken away at its edge to show the disposition of the fabric more clearly.

Figure 3 is a perspective view of a length or strip of fabric showing the manner in which it is folded prior to and during its introduction into the edges of the board, and

Figures 4 and 5 are cross sectional views similar to Figure l, showing modified edge constructions for wall board using a fabrlc esI the edge oredge faces is applied a, la er of fabric extending the full width thereo this fabric, as will presently be seen, having the form of a narrow strip or tape 3 which is applied along the edges in the process of manufacture. Moreover, the fabric covering 4 strip includes an inwardly projecting porplied, the

tion 3a extending at right angles to the edge faces midway between' the coveringl sheets. This inwardly extending ortion is made up of two plies of the abric, generall formed by folding the strip double, em ding the folded edge portion edgewise into the `open edge 'of the board and midway of its th1ckness,'with rotruding marginal portions 3b, 3b of su cient width to be folded in op osite directions and cover the ex edge ace of the plaster core on either slde of the embedded portion of the strip.

Considering the material as a continuous strip of woven mesh vfabric., the same assumes the dshape of a T, with its base rtion 3a of double thickness extending gewise into the core a distance of from e@ to 1 inch, thus providing a reinforcement for' the ed and two plies of fabric through 'which At e nails are driven in applying the board to a wall and the two edge portions 3b, 3b of a single thickness, folded at right an les to the embedded portion 3a and laid atwise a inst the exposed faces of the body, with t eir outer edges ,coinciding with the edges of the covering sheets. Inasmuch as the Iplaster body is in wet or plastic condition when the fabric'strips are inserted and apgressure exerted along the led e of theboard orees the wet plaster throug the interstices ofthe mesh thus firmly embedding the material in the plaster and leavin a smooth finished surface at the edge.

-le a number of practical methods ay be used for manufacturing a board of a kmd 'such as described, the following is believed to be as satisfactory as an :Assuming that the wall board is to be of tli'e standard thickness .of *ya of an inch, the width of the mesh fabric y-ueled wouldbe about 2 inches. The fabric would be wound in rolls either single or folded double, and fed therefrom in the same 'manner as thepaper covering sheets. The

material itself is relatively inexpensive not unlike cheese cloth or cheap muslin, which hasbeen starched or sizedto make it fairly stl--in fact, it may be material of the same character used in the lining of garments.

Figure 3 is a diagrammatic illustration ofthe manner in which a strip of sin le thickness mesh fabric would be insertedg into the edge of the board as made by the continuous process. The material is fed from rolls mounted on suitable spindles located Aadjav cent the point where the materialenter's the Ywet laster. On leavin Y the rolls as avilat or strix asfat A, gure) it would `paca t rough suitable folders which wall. The vgrooves ill with. the

would fgld it double with its folded edge.

inwardly and the free edgesA outwardly, as at B, the stiffness ofthe material making it readily foldable with a sharp crease only at its folded edge as at b. B means of ide rolls the folded strip woul then be led orizontally between the edges of the two covering sheets and into the mass of wet plaster between the two, so thatthe greater rtion of the folded strip would be embedde in the laster as the materials passed between the orming rolls. The'free edge portions of the' Figure 3 shows the successive folded positions ofa continuous strip of the mesh fabric fromwthe time it leaves the ro'll to its incorporation in the board, it is understood that each folding operation would take place in its proper relation to the progress of the board through the manufacturing process, with the Proper guides and folding devices to contro the strips a` either edge of the board. In case the m h fabric is initially in double folded form as at B, it would then .be introduced directly into the edge of the board and then folded into T form as at C.

It is preferred to form` a groove 4 in the edgeeface of the board at the junction of the em dded portion 3a of the fabric strip and the two edge portions 3b, 3b, (Figure 2), this groove being formed by a suitable pointed groovin tool mounted in the path of the edges o the board and pressing into Ithe surface while the plaster mass is still wet. Such a groove isl advantageous as a means of holding the crack-filling material, which is usuall applied along the joint between the edges o two wall boards, when nailed to a plastic crack-filling material to form ke s which revent the same from falling out a r it has r1 Wall'board provided with a fabric covered 'the fabric e ibits a pronouncedr tion on the plaster by p the above and below ing to increase formation on setting and thus further tendthe strength of the plaster at the ed e. i

Asi e from the manner of using and introducing a fabric covering and reinforcing material into the edge of wall board already disclosed, other ways and means may be rea ll ily devised and adopted. For instance, Fig.- .ure 4 shows a stripv 5 of fabric folded in U-shape-instead of T-shape and inserted in somewhat the same manner into the edge of the board. In this form the edge portions 5a, 5a of the strip extend into-the plaster bodyV just beneath the edges of the covering* sheet. Aga-in in Figure 5, two narrow strips 6, 6 may be introduced into the edge instead of the single U-shaped strip as in Figure 4. In this instance the outer edges of the strips may meet along the center line ofthe edge face, either -with a narrow space between, in abutting contact or overlapplng so that there is a double thickness of fabric over part or the entire width/of the edges. Having set forth a preferred embodiment of my invention,

I claim: 1. A wall board comprising a plaster body, covering sheets of fibrous material extending over the top and bottom faces of said body and a strip of mesh fabric applied over the edge face of said body and having a portionf thereof extending into said body.

2.v A wall board comprising-a plaster body, covering sheets of fibrous material extending over the top and bottom faces of said body and a strip of mesh fabric applied along the edge face of said body and having a portion thereof folded double and embedded in said body at ri ht angles to said edge face.

3. A wa lboard comprising a plaster body, .coverin sheets of fibrous material on the oppositel aces of said body, and strips of mesh fabric applied to the side edge faces of said body and having sections folded to project laterally into said body for a predetermined distance.

4. A wall board comprising a plaster body, covering sheets of fibrous material on the opposite faces of said body, and a strip of mesh fabric applied to a side edge face of said body and consisting of a portion folded double a and extending edgewise into said body for a l predetermined distance, and marginal portions folded over against the edge face of said body.

5. A wall board comprising a plaster body, covering sheets of fibrous material on the opposite faces of said body, and a strip of relatively stif mesh fabric folded into substantially T.form, with one portion of double thickness extending edgewise into said body substantially midway its thickness .and the remaining portions folded in opposite directions against the edge face of the body.

6. A wall board comprising a plaster body,

. covering sheets of fibrous material on the opposite aces of said body,.and extending to the side edges thereof, and'strips of relatively stiff mesh fabric folded into substantially T-form and applied along the side edges of said body, with one portion of double thickness extending edgewise into said body substantially midway its thickness and the remaining portions folded back and pressed into the edge face of the body.

7 A wallboard comprising a plaster bod covering sheets on opposite sides of said bo yv and terminating at the side edges thereof, and a str1 of mesh fabricfoldedin substantially T- orm and applied to the edges ofsaid body with one portion at the edge sur face and the other. portion extending edgewise into said body.

8. A wallboard comprising a plaster body, covering. sheets on opposite sides of the bod and terminating at the side edges thereo and a strip of mesh fabric applied to said edges, said fabric being folded to providea portion of substantially the width of the` consisting of continuously advancing sheetsy of covering material toward a pair of pressure rolls, feeding wet plaster into the lower coveringl sheet in advance of said pressure rolls, feeding a strip of woven mesh fabric toward the advancing edges of said covering sheet, folding said strip longitudinally as it is being fed to provide an edge portion of doubleV thickness, guidin said strip into the path of the advancing e ges of said covering sheets and plaster, whereby said edge portion of the strip is embedded edgewise in the plaster and attening the remaining portion of the strip against the edge faces of the plaster.

l. A- process of covering the edges of said wallboard in the course yof manufacture by a continuons process consisting of feeding strips of mesh fabric from rolls toward the path of the advancing edges of the board,

folding the strips double, guiding said jectin'g edge portions against the edge faces l of the plaster.

12. A process of covering the edges of lthey are advanced, guidin said folded strips edgewise yinto the path o the edges of the board so that their inner edge portions are.

embedded in the plaster and flattening the outer marginal portions against the edge face of the plaster. 'v 13. A plaster board com rising a plaster core, top and bottom covering sheets, and a fabric strip adhered to the edge of the core, said stri having a lateral member extending into an anchored in the core.

14. A wallboard comprising a plaster body, sheets of fibrous material covering the .top and bottom faces of said bod and a strip of mesh fabric folded to provi e angularly disposed portions, one of single thickness being applied parallel to the edge face of said body and another of double thickness extending edgewise into said body.

15. A lwallboard comprising a plaster body, sheets of fibrous material covering the of the edge face of sai top and bottom faces of-said body and a strip of mesh fabric folded longitudinally to form angularly disposed portions,one portion of single thickness being e ual in width to that body and applied over the same, and `the other being of double thickness and extending edgewise into said body from its edge face.r

16. A wallboard i comprising y' a plaster v body, sheets of brous material covering the opposite faces of said body and .terminating at the edges thereof, and strips of mesh fabric folded lengthwise to form angularly disposed portions, one portion being of double thickness and exten ing edgewise into said l body substantially midway of its thickness,

and the other portion of sin -le thickness being applied against the edge ace of said body between the edges of said sheets.

17. A wallboard com rising a plaster body, covering sheets of brous material on the opposite faces of said body, and a strip of mesh fabric applied along the edge face of said body and consisting of a portion folded double and embedded edgewise into said bod and portions of sin le thickness exten ing at right an les to said first-mentioned portion and applic to said edge.

18. A .'wallboard com rising a plaster body, covering sheets of brous material on the opposite faces of said body, and a Vst'ip of relatively stiff mesh fabric folded longitudinally into substantially T-form, 'with one portion ofjdouble thickness extending edgewise into said body substantially midway its thickness, the remaining portionsof single thickness extending in op osite directions and a plied to the edge throug out its width.

l path of an advancin foldin the strip longitudinally as it is advthe ace of the body v 19. A] wallboard com rising a plaster body, coverin sheets of brous material on the opposite aces of said body, and extending to the side edges thereof, and strips of relatively stiff mesh fabric folded into substantially T-form to rovide a4 portion of double thickness extending edgewise into said body substantially midwayv its thickness and portions of singlethickness extending in opposite directions from said first-mentioned 20. A process of treating the edges of wallboard being made by a continuous process,

consisting of feeding a strip of mesh fabric against the edge face o the board.

21. A process of manufacturing wallboard consisting of continuously advancing sheets f of covering material toward a pair ofpressure rolls, ceding wet'plaster upon the lower covering sheet in advance ,of said pressure rolls, feedin strips of mesh fabric toward the edges o the advancing board, folding the advancing strip longitu portion of double thickne, gu folded strip into the edge of said advancing boardwith 'said portion of double thickness foremost and disposed edgewise, and applying the remaining portions of said'strip to the ed e faces of the laster. v n f 22. rocess of reinforcing the edges of wallboar in the course of manufacture by a continuous process consistin of continuously feedin stri s of mesh fa ric toward the ath of t e a vanc'ing edgesl of the board,

oldin the strips as they are advanced to provi e a marginal ortion-of double' thickness, guiding said fo ded strip into the edges of the board with the portion of double thickness entering the plaster edgewise, and "apinally to forma I iding said A plying the remaining'portions ofthe strips of narrow mesh fabric from'a lroll toward the edge of the board,

Vance', guiding said folded strip edgewise into the bedded in the plaster, and flattening its outer marginal portions against the'edgeface of Plaster. i 'y .f-ur" 1? Signed atPort March, 1928. 'A

GUsTAvn- ADOLPH NEW.'

Clinton this-.falsil day" of ath of the ed e of the board so 'that its inner folded e ge portion`is 'ein 

